Percussion drill motor



March 31, 1970 M. E. SCHINDLER 3,503,459

PERCUSSION DRILL MOTOR 4 Sheets-Sheet 1 Filed July 29, 1968 Marv/n E. Jc/wnd/er INVEN'I'OR.

A r 7' ORA/E VJ March 31, 1970 M. E. SCHINDLER 3,503,459

PERCUSSION DRILL MOTOR Filed July 29. 1968 4 Sheets-Sheet 2 asw ATTORNEY March 31, 1970 M. E. SCHINDLER 3,503,459

PERCUSSION DRILL MOTOR 4 Sheets-Sheet 3 Filed July 29. 1968 HHW srllg Mar w 6'. JrA/nd/er INVEN'IOR.

March 31,

M. E. SCHINDLER PERCUSSION DRILL MOTOR Filed July 29. 1968 IIZO 4 Sheets-Sheet 4 /2/ Mar w 6'. Jrb Ind/er INVENTOR.

nrrae/ver United States Patent 3,503,459 PERCUSSION DRILL MOTOR Marvin E. Schindler, Houston, Tex., assignor to Mission Manufacturing Company, Houston, Tex., a corporation of Delaware Filed July 29, 1968, Ser. No. 748,413 Int. Cl. E2lc 7/10 U.S. Cl. 17380 6 Claims ABSTRACT OF THE DISCLOSURE This application is directed to a down-hole type percussion drill motor comprising a rugged casing forming the working chamber in which a hammer piston reciprocates and including operating fluid passages, yet adapted to Withstand the tensional, compressive, torsional, and other forces, abrasions, and blows to which such a motor is subjected in normal operation with minimum thickness of metal. Maximum operating efficiency is assured by the provision of ample pressured working fluid passages of segmental section which are formed between integrally united, interfitting barrels, while exhaust from the rear working chamber flows through a passage in the center of the hammer piston.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to down-hole type percussion drill motors and consists particularly in such a motor having working fluid and exhaust passaging and valved ports of maximum size for a particular casing outside diameter to insure optimum charging and exhausting of the working chambers and resultant maximum output and efliciency of the drill motor.

Description of the prior art In previous percussion drill motors of the above type, where fluid passaging, either for working fluid or exhaust or both, is provided in the motor casing, such passages customarily have been formed by the provision of flutes or grooves in the casing wall which are closed by a separate, relatively thin sleeve which is secured, usually by threads, to the casing or the casing heads. Since such sleeves are not load carrying or blow resisting members, they, necessarily, tend to reduce the transverse area of the working chamber and the hammer piston which reciprocates therein. In other instances, one or more of these passages are formed in a stem or tube which passes centrally through the working chamber and the hammer piston, and these stems or tubes have resulted in constructional and maintenance problems while also tending to reduce the working areas of the piston.

SUMMARY OF THE INVENTION It is an object of the present invention to provide the down hole type percussion drill motor in which certain of the operating fluid passages are provided in the casing Without the necessity of increasing the thickness of the casing as, for instance, by the provision of the separate, non-structural passage closing sleeve, as mentioned above.

Another object is to provide such a motor in which the entire thickness of the casing material serves structural load Carrying function.

Another object is to provide operating fluid passages in the casing While eliminating the possibility of leakage from the passages.

Still another object is to provide a percussion motor well adapted to resist the forces and blows to which a down-hole type motor is subjected and yet which has maximum power output.

ICC

These objects and others are attained by the structure illustrated in the accompanying drawings which consist of a percussion motor casing having a top sub or adapter member which secures the same to a supporting drill pipe and forms a working fluid connection between the drill pipe and the working chamber within the casing. The casing is formed by closely interfitting concentric barrels in the mating surfaces of which there are provided a plurality of fluid passages of segmental section for corn ducting the working fluid to opposite ends of the working chamber. These interfitting barrels are welded together so as to form an integral, load-carrying casing of adequate strength proportions and in which leakage cannot occur from the working fluid passages. The exhaust from the rear working chamber occurs through an axial passage in the hammer piston, while the exhaust from the forward working chamber occurs through an axial duct in the anvil which is sliclably supported at the forward or lower end of the casing. Finger valves on the back head and anvil alternately enter the axial passage in the hammer piston at the ends of the piston stroke to cut off the exhaust from the working chambers.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which illustrate the invention,

FIG. IA is a half longitudinal section and half side view, with parts being broken away, illustrating the rearward or upper part of the novel percussion motor.

FIG. 1B is a similar view showing the lower part of the motor.

FIG. 2 is a longitudinal section illustrating the central part of the motor with the hammer piston in its striking position.

FIGS. 3 and 4 are transverse sections taken on lines 3--3 and 4-4, respectively, of FIGS. 1A and 2.

FIGS. 5A and 5B are half longitudinal sections illustrating, respectively, the upper and lower parts of the motor in the hanging, otbbottom position.

FIG. 6 is a partial central longitudinal section illustrating a modification.

FIGS. 7 and 8 are transverse sections taken on the corresponding section lines of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A and 1B show the motor in its on-bottom operating position with hammer piston 7 in its rearward, turn-around position. The working chamber in which piston 7 reciprocates is formed by a casing, generally designated 8, formed of a first barrel including upper and lower cylindrical portions 9 and 10 and a reduced intermediate portion 11, and an outer intermediate barrel-forming portion including initially split halves 12 and 13. Upper barrel portion 9 is internally threaded at 14 for attachment to the threaded lower extremity 15 of a top-sutnor adapted member 16 which has an internal thread 17 at its upper extremity for attachment to the threaded lower extremity of a sup porting drill pipe string (not shown) in the usual manner. The central orifice 18 in top sub 16 serves to di rect pressured working fluid supplied through the drill pipe string to the upper and lower working chambers 19 and 20 of the motor at opposite ends of hammer piston 7. Split barrel parts 12 and 13 are integrally secured together and to barrel parts 9 and 10 by welded seams 21, 22, 23, and 24.

Lodged between the casing and top sub 16 is the supporting flange 26 of a generally cupshaped check valve guide 27 having a bottom wall 28 with a central aperture 29. Slidable in guide 27 is the shank 30 of a generally conical check valve 31 which is constantly urged upwardly in the guide by a coiled compression spring 32 so that when the tool is at rest, check valve 31 will engage a tapered seat 33 in the top sub to prevent the entry of ambient fluids into the motor. Operating fluids supplied through passage 18 drive check valve 31 downwardly to permit the fluid to enter the working chambers of the motor. Guide flange 26 is secured in position by a stepped tubular member having an upper portion 34 rather closely received within the casing and a fingerforming lower portion 35 of reduced diameter. An external shoulder 36 on upper portion 34 rests against a shoulder 37 within the casing. Flanges 26 and 36 are sepaarted by a sealing gasket 38.

Threaded at 40 in the lower part 10 of the casing is a chuck or driver-sub member 41 having internal splines which slidably but nonrotatably receive complementary splines 42 on the intermediate shank portion 43 of an anvil, generally designated 44. At the upper end of the anvil there are provided stepped cylindrical portions 45 and 46, the latter terminating in a striking head 47 having an overhanging shoulder 48. The upper portion 49 of driver-sub member 41 has oil grooves 50 and slidably receives and guides portion 45 of the anvil. A split stop ring 51 is loosely received about portion 46 of the anvil and is held in position by driver-sub 41, as shown. An additional split stop ring 52 is also provided in the inner wall of the casing just above ring 51. At the lower end of the anvil there is provided, in this case integrally, a cutting bit 53 of any suitable design. An annular shoulder 54 on the bit supports member 41 at the lower end of the casing in the on-bottom operating position of the drill (FIG. 1B).

An exhaust duct 56 extends axially through the anvil and terminates at its lower extremity in inclined passages 57 for directing exhaust outwardly through the cutter for flushing the bottom and side walls of the hole and bit. The upper extremtiy of exhaust duct 56 is countersunk and receives a tubular finger member 58 which is yieldably secured in position by a resilient packing 59.

Extending axially through hammer piston 7 is an exhaust passage 61 which is of a diameter to freely receive bottom finger 58 when the hammer piston is in its lowermost position. Exhaust passage 61 also freely receives at its upper extremity previously-mentioned upper finger member 35 depending from the top sub or adapter 16.

A choke or metered plug 62 inserted within finger member 35 controls a constant bypass of working fluid through the motor, as will be explained. Upper portion 34 of the stepped member 34, 35 is provided with sealing rings 63 and 64 for engaging the casing inner wall. The body portion of check valve guide device 30 is thickened, as at 65, and there provided with a plurality of vertical passages 66 which connect passage 18 in top sub 16 with a chamber 67 between members 27 and 34, 35.

A series of pressure ports 70 in the larger portion 34 of stepped member 34, 35, conveniently four in number arranged symmetrically about the member, are located between sealing rings 63 and 64 and abreast of a similar circumferential series of pressure ports 71 in the reduced median casing barrel portion 11. A similar annular series of ports 72 (FIG. 2) are provided near the lower extremity of said inner barrel portion 11. A third series of pressure ports 73 are provided upwardly of the center of reduced inner barrel portion 11. All of the pressure ports 71, 72, and 73 are arranged in vertically aligned sets and each set is connected by a pressure passage 74 of generally segmental section extending between casing barrel portions 11 and 12 or 13. As indicated in FIGS. 2 and 4, these vertical passages are formed by segmental flats, as at 75, on inner casing barrel portion 11. In order to prevent leakage from passages 74 and also in order that the entire thickness of abutting barrel portions 11 and 12 and 13 form tensional, compressive, and torsional load-carrying casing structure, the outer barrel halves 12 and 13 are welded along their edges, as at 21, 22, 23, and 24, to the abutting edges of upper and lower barrel parts 9 and 10 and to the abutting vertical edges of each other.

The hammer piston 7 is of generally cylindrical shape for reciprocation within the casing and includes restricted annular slots 78 and 79 and a more extended central annular recess 80 forming upper and lower lands 81 and 82 and intermediate lands 83 and 84, all provided with circumferential oil grooves, as shown. Connecting annu lar grooves 78 and 79, respectively, with the upper and lower faces of the piston are annular series of vertical passages 85 and 86. As shown in FIG. 4, eight of these passages are provided in each set.

In operation, the novel percussion drill may be run into a well suspended at the lower end of a drill pipe string, in the usual manner. At such time, anvil 44 will hang abnormally, as shown in FIG. 5B, with its overhanging head 47 resting on stop ring 51 and annular shoulder 54 spaced substantially below the lower extremity of driver-sub member 41 at the bottom of the casing. In case working fluid is supplied at this time, it will simply flow directly through choke 62 in upper finger 35, now uncovered pressure ports 73, axial passage 61 in hammer piston 7, lower finger valve 58, and exhaust ducts 56 and 57 in the anvil, This will effectively prevent any pressured working fluid from being discharged into the lower working chamber 20 for causing actuation of the hammer piston. Such blowing" may be produced at any time, for instance, for the purpose of cleaning out debris at the bottom of a hole, by lifting the motor sufficiently to suspend the anvil abnormally forwardly, as shown in FIG. 5A.

When the tool reaches the bottom of the hole and sufficient weight is applied to the casing to cause the lower extremity of driver-sub member 41 to rest upon shoulder 54 of the bit, provided working fluid is supplied, the hammer pison will start to reciprocate within the casing to beat upon the anvil and thereby apply percussive blows to the bit. FIGS. 1A and 1B show the hammer piston at its rearward turn-around position in which the lower end of exhaust passage 61 in the piston has been withdrawn from finger valve 58, thus exhausting lower working chamber 20 through anvil ducting 56, 57. At the same time, upper pressure ports 73 will be abreast of annular groove 78 in the hammer piston, causing the supply of working fluid from ports 70 and 71 and segmental shaped passages 74 through groove 78 and vertical passages 85 to upper working chamber 19. This will cause the downward stroke of the piston. FIG. 2 shows the hammer piston in its lower striking position in which the upper end of piston exhaust passage 61 has been withdrawn from upper finger valve 35 exhausting upper working chamber 19, while the lower end of passage 61 now envelops lower finger valve 58 cutting off the exhaust from lower working chamber 20. Lower piston groove 79 is now abreast of lower pressure ports 72 causing the supply of pressured working fluid from passages 74 through vertical passages 86 to the lower working chamber. Since upper pressure ports 73 are now closed by piston land 81, the piston will reverse its stroke and the cycle will be repeated.

Due to the location of pressure fluid passages 74 within the confines of the rigid, integral causing and the elimination of special, non-structural passage forming sleeves, and the designing of passage 61 through the hammer piston to such area only as is necessary for an eflective exhaust, a maximum working area of the piston is available at each end without in any way weakening the casing. This structure also ensures effective sealing of the pressure passages in the casing, since no threaded seals are relied upon. it has been found that these improvements result in materially improved breathing of the motor and materially increased frequency, work per cycle, and

total power output. Special reference is made to the ample pressure passages which are formed by the four segmental shaped passages 74 extending between integrally welded barrel portions of the casing and to the adequate pressure portion at 71, 72, and 73. Because of the location of the passages and ports in the integral, structural casing, their sizes may be increased to whatever degree is necessary to insure adequately rapid filling of the working chambers which, in turn, insures maximum frequency and power output. At the same time, exhausting through central piston passage 61 and anvil passage 53 will contribute to the optimum efiiciency of the operating cycle. The mounting and guiding of anvil 44 entirely within driver-sub member 41 also facilitates construction and maintenance of the tool, since assembly is effected simply by initially assembling the split driver-sub parts 41 about the anvil, then screwing this subassembly as a capsule unit into the bottom end of the casing. No part of the casing is relied upon for guiding of the anvil and, thus, only the guide surfaces between the driver-sub and anvil need be accurately constructed.

The form in FIGS. 6, 7, and 8 has certain advantages, particularly in the prevention of leakage from the high pressure passages into regions being exhausted. As in the first form, the working barrel is assembled from a portion 87 having top and bottom cylinders 88 and 89 and a reduced intermediate cylinder 90 about which is received outer sleeve halves 91 and 92 welded longitudinally at 93 and 94 and at their tops and bottoms at 95 and 96. Four main high pressure fluid supply slots are pro vided at 97, 98, 99, and extending from annularly arranged ports 101 in back head structure 102 to center feed ports 103 in the upper half portion of reduced inner cylinder 90. Opposite these main high pressure slots or passages are four top feed slots 104, 105, 106, and 107 extending between longitudinally spaced sets of ports 108 and 109. Longitudinal welds 93 and 94 effectively seal adjacent passages 97 and 104 and 100 and 107 to prevent leakage therebetween when upper working chamher 110 is being exhausted.

In the lower portion of reduced inner cylinder 90 there are provided bottom high pressure fluid slots 111, 112, 113, and 114 extending between longitudinally spaced ports 115 and 116. Adjacent feed slots 115, 113 and 115, 111 are sealed by longitudinal welds 94 and 93. If desired, the entire barrel structure including 'parts 88, 89, 90, 91, and 92 may be integrally formed with the slots properly cored, and in this case, ofrcourse, leakage between the groups of slots would be prevented.

A shuttle recess 117 surrounds the central part of piston 118 through which axial exhaust passage 119 passes. The upper and lower extremities of passage 119 are adapted to slidably receive back head finger 120 and bottom finger 121 projecting from the anvil, as in the previous form.

In operation, upper main feed slots 97-100 will be constantly filled with high pressure fluid. When piston 118 is in its lowest position, striking anvil 122, this high pressure working fluid will be led through ports 103 and shuttle recess 117 to ports 115 and bottom feed slots 111-114, thence through bottom ports 116 into bottom working chamber 123. Since upper finger valve 120 at this time will be out of passage 119, upper chamber 110 will exhaust through piston passage 119 and the anvil and the piston will rise. As the piston approaches its uppermost position, finger valve 120 will enter passage 119, ports 115 will be cut oil, and shuttle recess 117 will overlap ports 109 feeding high pressure working fluid through slots 104-107 and ports 108 to upper working chamber 110. Since at this time the lower end of passage 119 will be separated from bottom finger 121, lower working chamber 123 will exhaust through the anvil and the piston will be driven downwardly to deliver a working blow upon the anvil.

Various features may be modified as will occur to those skilled in the art, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

1. A percussion drill motor of the down-hole type comprising an integral casing forming a working chamber, a top sub at the rear end of said casing for attachment to a supporting column and including a connection for the supply of working fluid, an anvil slidably received in the forward part of said casing and carrying drill bit means, a hammer piston reciprocable in said casing, working fluid passage means extending from said connection to opposite ends of said working chamber, an exhaust duct extending through said anvil, and valving means con trolling the supply of working fluid to opposite ends of said chamber and exhausting of said chamber opposite ends through said duct to cause said piston to beat upon said anvil, said casing being formed of telescopingly interfitting cylindrical wall parts integrally formed as a structural unit for carrying torsional, axial, and radial loads between said top sub and said anvil, said working fluid passaging being formed at least in part between said casing walls.

2. A percussion drill motor as described in claim 1 further including an exhaust passage extending axially through said piston and in which said valving means includes finger-like projections, respectively, on said back head and one of the adjacent parts of said piston and said anvil for controlling the alternate exhausting of the opposite ends of said working chamber through said exhaust passage and said duct extension.

3. A percussion drill motor as described in claim 1 in which the part of said working fluid passaging between said casing walls is circumferentially elongated in cross section to increase the capacity thereof.

4. A percussion drill motor as described in claim 1 in which a plurality of working fluid passage parts extend longitudinally through said casing and further including ports connecting each of said passage parts with said connection and with opposite ends of said working chamber.

5. A percussion drill motor as described in claim 4 in which each of said passage parts is of circumferentially elongated cross section.

6. A percussion drill motor as described in claim 1 further including ports connecting said passage part, re spectively, with opposite ends of said working chamber, said hammer piston being longer than the distance between said ports and having recessing for respectively connecting said ports and said chamber ends at the ends of the piston stroke.

References Cited UNITED STATES PATENTS 2,947,519 8/1960 Feucht 17330 X 3,011,570 12/1961 Kurt 17380 3,105,559 10/1963 Collier 173-73 X 3,162,251 12/1964 Bassinger l7380 X 3,167,136 1/1965 Cook 173-80X 3,193,024 7/1965 Cleary 17380 X 3,198,264 8/1965 Oelke 17373 3,311,177 3/1967 Collier l7380 X NILE C. BYERS, JR., Primary Examiner U.S. Cl. X.R. 175-296 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,503,459 Dated March 31 1970 Inventor(s) Marvin E. Schindler It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line Tl, "FIGS. 2 and t" should be FIGS. 3 and I Column 5, line 5, "portion" should be porting SIGNED AND SEALED JUL 2 8 1970 Atteat:

Edward M. Fletcher, It.

mommmm x. m.

Gonnissionar of Patents 

